A) Right angled
B) Obtuse angled
C) Equilateral
D) Isosceles
Correct Answer: C
Solution :
\[\frac{\cos A}{\cos B}=\frac{a}{b}=\frac{\sin A}{\sin B}\] Þ \[\sin A\cos B=\sin B\cos A\] Þ \[\sin (A-B)=0\] Þ \[\sin (A-B)=\sin 0\] Þ \[A-B=0\] Þ \[A=B\] Similarly, \[A=B=C\]. Hence it is an equilateral triangle.You need to login to perform this action.
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